1. Field of the Invention
The invention relates to an electromagnetic drive for a focal-plane shutter of a camera having two light-excluding shutter curtains, each of which has its own linear motor constructed from permanent magnets and electromagnetic coils.
2. Background of the Invention
A drive is described, for example, in DE 26 16 636 C3. However, drive mechanisms which are driven by mechanical prestressing devices, such as springs and the like, are still usually used for achieving the traversing movement of shutter curtains in portable cameras having focal-plane shutters. These known shutter drive mechanisms require a stressing device which, after completion of an exposure, returns the shutter curtains into the starting position and thereby stresses the springs, so that the next exposure can take place. This additional return mechanism complicates the overall shutter system and increases the number of components required, thereby increasing the production and assembly costs. In addition, many of the current motor-operated cameras have a motor-gear unit that operates the stressing device.
These difficulties or problems with known drive mechanisms are not intended to be exhaustive, but are among many tending to reduce the desirability of the known drive mechanisms. Other notable problems may exist; those presented above, however, should be sufficient to demonstrate that devices appearing in the past are amenable to worthwhile improvement.